Having friends who are big time fishermen, I have had the chance to fish both lake and ocean. If it were a matter of survival I would pick the lake. I have caught way more fish in a lake than the ocean. But if it were a matter of just being out and relaxing with friends I really liked the ocean. Of course the fish I caught in the ocean weren't as many but sure were good.
I'll go a different way with this. Growing up in a fishing community I'd take the ocean for making a living and if it were convenient and affordable to own all of the expensive equipment that go with ocean fishing (boat, large rods/reels, long day trips, fuel, mooring, etc).
If we're talking about small numbers survival, or just casual fishing with minimal cost outlay, give me a good lake and a canoe every time. It's safer, it's easier, and you're not nearly as feast or famine.
It's a lot easier to dig up a few worms and pull in some small fish than it is to arrange a day trip 10 miles from shore.